2005 Big Hit FSR suspension upgrade

like the title says I have a 05 big hit FSR. Im wanting to upgrade the forks and shock, Im going with the new '12 Fox 40 FIT RC2 on the front... I really wanna put the the new '12 FOX DHX RC4 on the rear. My question is the stock shock is a 8.75x2.5 and the only size I can get is a 8.75x2.75... Can I run this shock or is the .25 gonna change alot... Also will I be able to clear the piggy back part of the shock?? thanks for the input in advance...

Cool thanks man!!! Well I got a super deal on a 2011 kona operator DH so I picked it up.. I am take the stock shock off the big hit and send it to push industries and throw a set of marzocchi forks on it.